柴达木盆地北缘塔塔楞环斑花岗岩的岩相学和地球化学特征  

Petrography and geochemistry of the Tataleng rapakivi granite on the northern margin of the Qaidam basin,northwestern China

作　　者：胡能高[1] 王晓霞[2] 孙延贵[3] 林伟[1] 申文环 陈运杰[1] 

机构地区：[1]长安大学资源学院,陕西西安710054 [2]中国地质科学院矿产资源研究所,北京100037 [3]青海省地质调查院,青海西宁810012 [4]山东省化工地质勘察院,山东济南250013

出　　处：《地质通报》2008年第11期1923-1932,共10页Geological Bulletin of China

基　　金：国家自然科学基金项目(批准号:40372043)资助。

摘　　要：塔塔楞环斑花岗岩是柴达木盆地北缘一个古生代复式岩体。该环斑花岗岩的主量元素具有富SiO2、K2O和FeO*,高K2O/Na2O和FeO*/MgO的特点,其平均值分别为72.86%、5.17%和3.35%,2.22和10.73;∑REE在279.1×10-6～300.3×10-6之间,(La/Lu)N为11.32～13.14,δEu在0.28～0.38之间;Ba、Rb、Pb、Th等元素的含量高,而Sr、Cr、Ni、V等元素的含量低。与经典环斑花岗岩相比,二者在岩相学上相同,在地球化学上也有相似之处,即该岩体也表现为高钾、富铁、富LREE和Eu亏损的特征,但部分微量元素与典型环斑花岗岩有一定差异。岩体的形成时代和区域构造背景的综合分析显示,该岩体可能是早古生代后碰撞或后造山伸展构造环境下的产物。The Tataleng rapakivi granite is a Paleozoic phiton on the northern margin of the Qaidam Basin. It has high contents in SiO2 （72.86%）, K2O （5.17%） and FeO＊ （3.35%）, high in K2O/Na2O（2.22） and FeO＊/MgO （10.73） on average. Its ∑REE is from 279.1 to 300.3 ppm, （La/Lu）N from 11.32 to 13.14 and δEu from 0.28 to 0.38; Ba, Rb, Pb and Th contents of the granite are high, while St, Cr, Ni, V contents are low. This rapakivi granite is similar to the typical rapakivi granites both on petrography and geochemistry except some trace elements, showing high in K, Fe and LREE, depleted in δEu. The age of the granite and regional geological integrated analysis suggest that this rapakivi granite intruded in a Late Paleozoic rift basin, showing an extension geological setting.

关 键 词：柴达木盆地北缘 塔塔楞岩体 环斑花岗岩 岩石地球化学 

分 类 号：P588.121[天文地球—岩石学] P595[天文地球—地质学]